An adult assumes the role of parent for a child other than his or her own biological offspring in the process of adoption. Legally recognized adoptions require a court or other government agency to award permanent custody of a child (or, occasionally, an older individual) to adoptive parents. Specific requirements for adoption vary among states and countries. Adoptions can be privately arranged through individuals or agencies, or arranged through a public agency such as a state's child protective services. Adoptees may be adopted singly or as sibling groups; and they may come from the local area or from other countries. Adoptive parents may be traditional married couples, they may also be single men or women, or they may be non-traditional couples. Parents may be childless or already have children.

Adoption is a practice that dates to ancient times. The Romans, for example, saw adoption as a way of...